Underground conduit for powerful electric currents



(No Model.)

2 Sheets-Sheet 1.

G. B. PENNOCK.

UNDERGROUND GONDUIT FOR POWERFUL BLEU TRIG GURRBNTS.

Patented Mar.. 22, 1887.. 129.1

Wl T NESSES ATTORNEY.

N PETERS. Phoevlilhogmphur. wnhlngwn, D. C.

(No M0681.) 2 sheets-sheet 2. G. B. PEN'NOGK.

UNDERGROUND OONDUIT EUR POWERFUL ELECTRIC GURRENTbS. No. 359,738. Patented Mar. 22, 1887.

UNITED STATES PATENT OFFICE.,

GEORGE BE PENNOCK, OF BROOKLYN, NEV YORK.

UNDERGROUND CONDUIT FOR POWERFUL ELECTRIC CURRENTS.

SPECIFICAEAION forming part of Letters Patent No. 359,738, dated March 22, 1887.

` Application tiled April 91, 1856. Serial No. 199,708. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE B. PENNooK, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of NewYork, haveinvented certain new and useful Improvements in Underground Oonduits for Powerful Electric Currents, of which the following is a specification.

My invention relates to improvements in underground conduits; and the object of my improvements is to provide a conduit that will conveyin condition for work powerful electric currents without injury to the conduit or surroundings. I attain this object by means of the structure illustrated in the accompanying drawings, in which- Figure l is an end view of a section of my improved electric -current underground conduit; Fig. 2, a top view of the same; Fig. 3, alateral view of two sections ofthe same placedA in line and united by a sleeve; Fig. 4., a side view of the sleeve with its water-proof cap removed; Fig. 5, an end view of the water-proof cap.

Similar letters refer to similar parts through out the several views.

It is necessary in order to construct a perfeet and durable underground cond uit for electric-light wires and electro-motive powers,that the entire structure should be one solid impermeable mass. Nohollow box or tubing will answer. Not a drop of moisture should penetrate the n exterior covering, and the conipounds used should be decay-proof, waterproof, and heat-proof. No insulation should be used that will corrode the conductors. The insulating material should be loose and porous, While the conductors should be well separated. This cannot be accomplished by using cables. The wires must be placed in their cells and lanes permanent and solid. They must be subjected to no strain. The sections of the conduit should be entirelyinished before leaving the factory. Man-holes, hollow boxes,and tubing should be avoided, for sooner or later they become sewers and water-conveyers, and as soon as underground electric-light wires are dampened the powerful currents in use on these circuits fail to act, as the faintest leak will cause the current to .burn to the iron tubing and to the ground.

Hollow structures are also a source of daugcr,as they readilylill with gas, which is caused to ignite bythe sparking ofthe bare wires in the man holes, causing explosions, hurling the man-hole covers high inthe air; and a case is known where the entire conduit for blocks was iilled with a ilaming fire, which melted the insulation, immediately grounding every circuit. The object of my invention is to produce for electric-light wires and for elect-ro motive power a solid underground conduit, so constructed, first, that the insulated electric-current wires shall be completely guarded against moisture; second, that the wires be widely separated from each other by tire-proof and heatproof i nsulations; and third,that the wires shall have a capacity to be readily tapped for lateral branches without removing the waterproof compound forming the main conduit.

The sections of the conduit are made in any convenient length and completely finished at the factory-that is to say, the electric-current conductors are adjusted in their several cells, which are formed in the outer surface of a solid` block of iireproofed wood and surrounded and packed tightly in mineral wool. The block is inclosed in a iireproofed wooden box of light material, or of boards composed of lireproofed paper, straw, or wood pulp, the block being enveloped in a thick packing of mineral wool. The inside conduit, now thoroughly insulated, is inclosed in a wooden case and enveloped with any good water-proof compound constituting asolid insulated impermeable mass. The sections thus made are laid in line in trenches a short distance apart and united by sleeves, within which the corresponding wires of neighboring sections are connected. Individual wires are caused to form loops for lateral connections by being` pushed and conveyed through apertures in opposite sides ofthe sleeves and caused to occupy deep grooves cut, for this purpose, in the exterior` of the sides of the sleeves. The looped wires C, apertures m, and grooves n are covered with moisture-proof caps or boxes. XVhen it-is de sired to attach lateral conduits, the water-proof caps or boxes are removed.

Referring now to Fig. l, A represents cells to receive the electric wires; B, a solid block of tireproofed wood; C, the electric-light wires and electro-motive-power wires; D, a packing of mineral wool,which acts as an absolute heatproof insulation; E, thick packing of mineral wool; F, aninside conduit of iireproofed wood, or of boards composed of ireproofed paper, straw, or wood pulp rendered fire-proof by :L thorough soaking in soluble glass; G, a solid mass ot'waterprooling; II, a wooden case.

In Figs. 2 and 3 I represents :L sleeve for uniting two sections-snch as .Tand K of the conduit.4 The sleeve I consists of a box of waterproofed wood, which closely overlaps the ends of sections J and K, and is screwed to them.

In Fig. 4, L represents glass tubing; m, apertures in the opposite sides of sleeves; 1L, grooves inside oi' sleeve; and in Fig. 5 O represents water-proof caps or boxes which cover the apertures m and grooves a. (Shown in Fig. 4.) These boxes consist cach of an inner box, I), an outer box, Q,of waterproofcd wood, with the intervening space, G, filled with any good water-proof compound, the inner boX,P, being filled with mineral wool resting on the grooves. The boxes when in position fit into rabbets or grooves It, Fig. 4, formed over the wirc-grooves, and are securely fastened to the main conduit by iron knees or brackets Figs. 2 and 3.

After the connection of the wires in the sleeves, the spaces therein between tbe wires are packed with mineral wool, and the space between the wires and the walls of the sleeve is filled with any good moistnreresisting coinpound, the wires being protected with a jacket ol' mineral wool.

I claiml. For electric-light wires and electronictive-power conductors, an underground couduit constructed in sections,each consistingof a solid impermeableinsulated heatproot' mass,

in which the wires are adjusted in longitudinal cells formed in solid blocks of fireproofed wood and packed in with mineral wool, which is inclosed in lire-proof and water-proof insulating xnaterials,the whole contained in aboard case, substantially as set forth.

2. In a moisture-proof underground conduit for electric-light wires and electro motivepower conductors, the combination of any seetion .I and its neighboring section K with a wooden sleeve, I, which is provided with one or more side apertures, m, glass tubing L, one or more grooves, n, into which the wires of the main conduit are looped and packed with inineralwool, covered with the removable moisture-proof caps 0,'for the purpose of facilitating the attachment of lateral electric-light con duits without disturbing the solidity of the main conduit.

3. For an electric-light underground and electro-motivepower conductor,a conduit constructed in sections, each consisting oi' a solid block offireproofed wood, B, with longitudinal cells A, bare wires G, mineral-wool insulation I), mineral-wool packing E, and `lire-prooi' inner conduit, F, the whole inclosed in waterproot' insulating materials, all contained in a casing, substantially as set forth, for the purpose of carrying and distributing powerful electric currents for lighting 'the streets or dwellings and for furnishing electro-motive power from central stations.

Signed at New York, in 'the count-y of New York and State ot' New York, this 19th day oi' April, A. D. 1886.

GEORGE B. IEFNOCK.

YVitncsses:

J. B. SABINE, WM. O. Minus. 

